Logic Link Control (LLC) Layer and Medium Access Control (MAC) layers are the sublayers of the Data link layer in the OSI reference model.OSI reference model: It stands as Open Systems Interconnection. OSI is a 7 layer architecture which contains 7 layers. Each layer has its own specific functionality. All these 7 layers in the OSI model are used to transmit data.Data Link LayerIn computer networking, the data link layer is the 2nd layer of the OSI reference model. The main function of this layer is to transmit data between nodes. The data link layer transmits data between network entities ... Read More

Modem stands for Modulator and Demodulator. It is a device that modulates signals to encode digital information for transmission and demodulates signals to decode the transmitted information.A modem transmits data in bits per second (bps).It is necessary for communication between digital devices and Analog devices.Modem is necessary because it acts as a translator between the devices and rapidly transmits the information.It converts the digital signal to Analog and vice versa to communicate between devices.It encodes the signal and decodes at the other end and vice versa between the devices.Building blocks of modem are shown in the diagram below −Types of ... Read More

The network troubleshooting tools are useful for every network administrator. These tools can be used to troubleshoot different network conditions.The network troubleshooting tools which are most used are as follows −RouteThe route utility is helpful to display the status of the routing table on host. The route utility is limited at the situations where the host has one ip address with one gateway. The route plays a key role at multiple IP addresses and multiple gateways.pathping / mtrThe pathping and meter utilities take the information obtained from tools and provide a more detailed picture of the characteristic path from particular ... Read More

IPSec is one of the secure techniques on the market for connecting network sites.IPSec was designed to supply the subsequent safety features once transferring packets across networks the following factors −Authentication − Verifies that the packet received is truly from the claimed sender.Integrity − Ensures that the contents of the packet didn't amend in transit.Confidentiality − Conceals the message content through secret writing.Use of Digital CertificateIt is explained below how IP security (IPsec) makes use of Digital Certificate.A digital certificate is an associate electronic document issued by a Certificate Authority (CA). It contains the general public key for a digital ... Read More

Mostly in the digital age, an enterprise Software-defined Wide Area Network (SD-WAN) can modernise your network and propel your business, while a single centralised SD-WAN can unify network connectivity and allow application delivery to be coordinated across an entire network.A WAN is a link separated by a significant distance between local area networks (LANs), anything from a few miles to thousands of miles. The word software-defined means the WAN is designed and managed programmatically. Therefore, it can be easily modified to meet evolving needs rapidly.Given below is the diagram of SD-WAN −Features of SD-WANThere are some features commonly attributed to ... Read More

Wide area network (WAN) is a telecommunication network that spreads over a large area of computer networking. A WAN network connects different small LAN and MAN networks.A well-known example of a WAN network is the Internet. It covers cities, states, countries and even continents. It can be a public network or a private network.WAN Network TechnologiesThere are two technologies which are used in the WAN network design. These technologies are explained below −Circuit SwitchingCircuit switched networks work on the principle of virtual connection that means all the messages will follow the same path and resources in this path are reserved ... Read More

Transmission Control Protocol/Internet Protocol (TCP/IP) are two different communication protocols. TCP defines the communication in a network and how to send data in the form of packets. IP manages how to make the route for packets to make sure it reaches its defined destination. Before data is sent its IP address is checked then it is determined where to forward the data.TCP/IP uses the same model as the OSI model. It uses the client/server model type of communication where a user or machine (a client) is provided a service by another computer (a server) in the network.TCP/IP has four layers ... Read More

Transmission Control Protocol/Internet Protocol (TCP/IP) are two different communication protocols. TCP splits a message to packets which were transmitted across the internet whereas the IP is accountable to address of every packet hence a chance to forward the exact destination.Previously, there was no TCP/IP and no method for the computers to perform effortlessly over public networks. The main function of TCP/IP is that it governs how the information is sent and received in the form of packets between source and destination.So in short, we can say that TCP defines the communication in a network and how to send data in ... Read More

Firewall in general is defined as a wall between personal computer and outside world. So it will filter the traffic coming from the outside world based on the user configuration like which sites are trusted sites and which we need to allow.Example of firewall system design is shown below −Components of a Firewall SystemThe components of firewall system are explained below −Perimeter RouterIt is used to provide a link to the public networking system like the internet, or a distinctive organization. It performs the routing of data packets with the help of an appropriate routing protocol. It also provides the ... Read More

Firewall is a wall between a personal computer and the outside world. So it will filter the traffic coming from the outside world based on the user configuration like which sites are trusted sites and which we need to allow.The diagram given below depicts the firewall:Functions of firewallThe functions of a firewall in computer networking are as follows −Block unsafe URLs.Close down a port completely.Open a port to only specific IP addresses.Allow some ip addresses at specific times.Advantages of Hardware FirewallThe advantages of a hardware firewall are as follows −Hardware firewalls can protect your entire network with a single firewall.Hardware ... Read More